void updateGraphicsTest(struct gameboy * gameboy)
{
//fill a frame buffer with some simple pixel data and see if it draws correctly
setLCDStatus(gameboy);
uint8_t previousMode = getCurrentMode(gameboy);
requestAnyNewModeInterrupts(gameboy, previousMode);
if (isLCDEnabled(gameboy)){
gameboy->screen.scanlineCounter += gameboy->cpu.previousInstruction.cycles;
}
else {
return;
}
if (gameboy->screen.scanlineCounter >= SCANLINE_CYCLE_TIME){
gameboy->screen.currentScanline++;
gameboy->screen.scanlineCounter = 0;
if (gameboy->screen.currentScanline == Y){
requestInterrupt(gameboy, int_vblank);
//printf("start vblank\n");
}
else if (gameboy->screen.currentScanline > (Y + NO_OF_INVISIBLE_SCANLINES)){
gameboy->screen.currentScanline = 0;
//printf("resetting scanline\n");
}
else if (gameboy->screen.currentScanline < Y){
// printf("drawing scanline %d\n", gameboy->screen.currentScanline);
drawScanline(gameboy);
}
else {
//printf("In vblank\n");
}
}
}
static void requestAnyNewModeInterrupts(struct gameboy * gameboy, uint8_t previousMode)
{
bool enabled = gameboy->screen.currentLCDInterruptEnabled;
uint8_t currentMode = getCurrentMode(gameboy);
if (enabled && (currentMode != previousMode)){
requestInterrupt(gameboy, lcdStat);
}
}
static void handleCurrentScanline(struct gameboy * gameboy)
{
uint8_t currentScanline = gameboy->screen.currentScanline;
if (currentScanline == Y){
requestInterrupt(gameboy, int_vblank);
}
else if (currentScanline > (Y + NO_OF_INVISIBLE_SCANLINES)){
gameboy->screen.currentScanline = 0; //reset
}
else {
drawScanline(gameboy);
}
}
static void doCoincidenceFlag(struct gameboy * gameboy)
{
if (gameboy->screen.currentScanline == readByte(gameboy, LY_COMPARE)){
//current scanline == the values stored at 0xFF45
//if this is true, set bit 2 of the status reg. Otherwise, reset it.
setBit(&gameboy->screen.status, COINCIDENCE_BIT, true);
if (isBitSet(gameboy->screen.status, COINCIDENCE_ENABLE_BIT)){
requestInterrupt(gameboy, lcdStat);
}
}
else {
setBit(&gameboy->screen.status, COINCIDENCE_BIT, false);
}
}
void Emu::Cpu::updateTimer(uint16_t m) {
uint8_t tmc = emu->mmu->rb(0xFF07);
bool timerEnabled = ((tmc & 0x04) != 0);
if (timerEnabled) {
timerClocks -= m;
if (timerClocks <= 0) {
setTimerFreq();
if(emu->mmu->rb(0xFF05) == 0xFF) {
emu->mmu->wb(0xFF05, emu->mmu->rb(0xFF06));
requestInterrupt(Timer);
} else {
emu->mmu->wb(0xFF05, emu->mmu->rb(0xFF05) + 1);
}
}
}
}
void serialFunc(int value) {
ioRam[0x01] = packetData;
requestInterrupt(SERIAL);
ioRam[0x02] &= ~0x80;
}
